For an inkjet head used in an inkjet printer or the like, ink is ejected selectively from a plurality of nozzles to form a picture on a recording medium.
As a method for ejecting ink from the nozzles of the inkjet head, there is the following method: the volume of a pressure chamber arranged for each nozzle is changed by an actuator and the ink in the pressure chamber is ejected when the volume of the pressure chamber is decreased by the actuator.
When the ink is ejected from a nozzle using such a method, the ink in the pressure chamber vibrates. It is assumed that such vibration (hereinafter to be referred to as residual vibration) has an adverse influence on subsequent ink ejections and may impact the quality of the printed image produced by the printer. This vibration problem can be alleviated/mitigated by forming an appropriate voltage waveform (driving signal) for driving the actuator.
However, as the viscosity of the ink varies with temperature, the damping state of the residual vibration of the ink also varies. Consequently, the residual vibration in the pressure chamber cannot be suppressed appropriately by only using a single sequence of voltage waveforms (driving signals) for driving the actuator.
The challenge is to provide an inkjet head that can suppress the residual vibration after ink ejection even with changes in ink temperature, so that high quality pictures can be formed, and to provide an inkjet printer/recorder having such an inkjet head.